Key Words.:

Abstract

Context:

Aims:This work presents a high–precision variability survey in the field of the old,
super metal–rich open cluster NGC 6791.

Methods:The data sample consists of more than 75,000 high–precision CCD time series measurements in the V band obtained mainly
at the Canada–France–Hawaii Telescope, with additional data from S. Pedro Mártir and Loiano observatories,
over a time span of ten nights. The field covers an area of 42×28 arcmin2.

Results:We have discovered 260 new variables and re-determined periods and amplitudes of 70
known variable stars. By means of a photometric evaluation of the membership in NGC 6791,
and a preliminary membership based on the proper motions,
we give a full description of the variable content of the
cluster and surrounding field in the range 16 ≲V< 23.5.
Accurate periods can be given for the variables
with P≲ 4.0 d, while for ones with longer periods the limited time–baseline hampered precise determinations.
We categorized the entire sample as follows: 6 pulsating, 3 irregular, 3 cataclysmic, 89 rotational variables and 61 eclipsing
systems; moreover, we detected 168 candidate variables for which we cannot give a variability class since
their periods are much longer than our time baseline.

Conclusions:On the basis of photometric considerations, and of the positions of the stars
with respect to the center of the cluster, we inferred that 11 new
variable stars are likely members of the cluster, for 22 stars the membership
is doubtful and 137 are likely non–members.
We also detected an outburst of about 3 mag in the light curve of a very faint blue
star belonging to the cluster and we suggest that this star could be a new U Gem (dwarf nova) cataclysmic variable.

The photometric precision achieved by several ongoing transiting planet searches
allows us to extend the census of variable stars down to very low amplitudes and faint
magnitudes in selected sky regions.
Variable stars are an important source of astrophysical information: from observations of them
we are able to test several theories (e.g., evolutionary and pulsational models).
Since all stars in an open cluster have essentially the same age, chemical composition
and distance, the study of variables which are cluster members can put more severe
constraints on the physical parameters. Comparisons can also be made between
the variable stars of the cluster and those of the surrounding field.

In this paper, we present the study and the classification of 260 new variable stars
that we found in the field of the open cluster NGC 6791, while for 70
already known variables we compare our results with the previous ones.
NGC 6791 (α= 19h 20m 53s; δ= +37∘ 46′18″),
is a rich and well studied open cluster.
It is thought to be the one of the oldest and probably the most metal-rich cluster known in our Galaxy.
Its age is estimated to be about 8–9 Gyrs (Carraro et al., (2006); King et al., (2005);
Chaboyer, Green, & Liebert, (1999); Stetson et al., (2003);
Kaluzny & Rucinski, (1995)); however,
the white dwarf cooling sequence indicates a different value, i.e., ∼2.4 Gyr (Bedin et al., (2005)).
The most recent estimates of its
metallicity are [Fe/H]=+0.39 (Carraro et al., (2006)),
[Fe/H]=+0.47 (Gratton et al., (2006)), and [Fe/H]=+0.45 (Anthony-Twarog et al., (2006)).
In this work we adopt for NGC 6791 a distance modulus (m−M)V=13.35±0.20 mag and a reddening
E(B−V)=0.09 mag (Carraro et al., (2006)).
The cluster is thus located at about 4.1 kpc from the Sun.

Because of its extreme characteristics,
NGC 6791 has been the target of many surveys (see Table 1
for a list of publications).
Taking into account the fact that in four cases the same stars have two identification numbers
(V15≡B7, V56≡V96, V76≡V85 and V77≡V88) and
counting also the stars B4 and B8, the total number of known variable stars in the
field of NGC 6791 to date was 123 (plus 7 suspected variables, proposed by Hartman et al., (2005)).

In Sect. 2 below we describe our observations,
in Sect. 3 we give details about the methods we employed
in the search for variable stars, which are themselves presented in Sect. 3.2.
In Sect. 4 we describe the properties of the variable stars,
focusing our attention on probable cluster members and some additional
peculiar cases.
The entire catalogue of variable stars is reported in an Appendix.

We surveyed NGC 6791 to detect the transits of extrasolar planets
(Montalto et al., (2007)).
The campaign covered 10 consecutive nights (from July 4, 2002 to July 13, 2002)
and it was characterized by the continuous monitoring of the target on each clear
night. Therefore, in addition to the planetary transit search, we could get access
to the full variability content at P≲ 4.0 d, both for the cluster and
the surrounding field.
Three telescopes were used:

The Canada–France–Hawaii Telescope (CFHT) in Hawaii equipped with the CFHT12k detector,
composed of 12 CCDs of 4128 × 2048 pixels and covering a field of
about 0.32 deg2.
Owing to the large number of bad columns, data from chip 6 could not be used,
so we could get data over a 0.29 deg2 field;

The San San Pedro Mártir (SPM) 2.1–m telescope equipped with the Thomson 2k detector
and covering a field of about 6×6 arcmin2;

The Loiano 1.5–m telescope equipped with
BFOSC + the EEV 1300×1348B detector and covering a field of 11.5×11.5 arcmin2.

Table 2 gives details about the length of the observing nights while
Figure 1 shows the field of the CFHT survey and the edges of the Loiano
and SPM surveys. The coordinates of the edges of our fields are also listed in Tab. 2.
The field of the SPM observations is entirely included within chip 9 and
the field of the Loiano observations partially covers chips
2, 3, 4, 8, 9 and 10 of CFHT (see Fig. 1).
The luminosities of the new variables range from V=23.2 mag to V∼16 mag
(near 1 mag above the turn–off); brighter stars are saturated.
The calibration of the CFHT, Loiano and SPM data have been performed
by using the Kaluzny & Rucinski photometry ((1995)).
More details on the data reduction procedure can be found in Montalto et al. ((2007)).

Loiano

SPM

CFHT

Night

tstart

tend

tstart

tend

tstart

tend

(HJD–2452400)

(HJD–2452400)

(HJD–2452400)

1st

59.82

59.96

2nd

60.83

61.02

3rd

62.48

62.63

61.68

61.95

61.94

62.07

4th

63.41

63.63

62.68

62.96

62.76

63.07

5th

64.38

64.64

63.68

63.96

63.88

64.10

6th

65.39

65.62

64.69

64.98

64.77

65.11

7th

65.70

65.82

8th

66.69

66.97

9th

67.67

67.98

67.77

68.10

10th

68.69

68.87

68.76

69.11

αmin

19h 20m 25\aas@@fstacks8

19h 20m 36\aas@@fstacks3

19h 19m 23\aas@@fstacks7

αmax

19h 21m 30\aas@@fstacks4

19h 21m 10\aas@@fstacks4

19h 22m 58\aas@@fstacks0

δmin

37∘ 41′22\aas@@fstack′′6

37∘ 43′15\aas@@fstack′′4

37∘ 36′6\aas@@fstack′′7

δmax

37∘ 53′42\aas@@fstack′′7

37∘ 50′3\aas@@fstack′′1

38∘ 4′21\aas@@fstack′′2

Table 2: The observation log for each night and the limits of the
field of view at the 3 different observatories.Figure 1: Field of view (42 × 28 arcmin2) of the CFHT image.
The chips are numbered in increasing order from left to right from chip 1 (top left) to chip 12 (bottom
right); stars of chip 6 are not plotted since we found it impossible to derive accurate
photometry. Dashed and solid lines are the edges of the SPM and Loiano fields, respectively.
Variable stars are also plotted: blue dots are pulsating variables, purple dots
are irregular and cataclysmic variables, green dots and cyan dots are
eclipsing systems (EA/EB–Type and EW–Type, respectively).
Finally, red and yellow dots are rotational and long–period variables, respectively.

The intensive monitoring of NGC 6791 allowed us to obtain tens of thousands of photometric
time series for stars located in, close to, and far away from the cluster center.
We have analysed 73331, 6055, and 2152 light curves obtained from the CFHT, Loiano and SPM telescopes respectively.
The CFHT, Loiano and SPM time series are composed of about 250, 60 and 170 datapoints, respectively.
The observations, intended to detect photometric transits, were performed in the V band only.

3.1 The search for variable candidates

To search for variable stars, we calculated the best “sinusoid plus constant” fit for
all light curves (Vanicek, (1971); Ferraz-Mello, (1981)).
We evaluated the goodness of the fit by calculating
parameters related to the reduction of the initial variance obtained by introducing
the periodic term. These parameters are the reduction factor (Vanicek, (1971)) and the
coefficient of spectral correlation S(ν) (Ferraz-Mello, (1981)).

Owing to the huge number of light curves, we need one or more parameters to
discover the variability.
Toward this goal, we considered the parameter r defined as
r=log10Smax, where Smax is the maximum value of S (i.e., the one corresponding to the frequency of the
best-fit sinusoid in the Ferraz-Mello method). If a star does not show variability the
introduction of a sinusoid does not improve the fit and then Smax is close
to zero (no variance reduction) and r≪0; on the other hand, a sine-shaped variability
strongly reduces the variance (S close to 1) and hence r=0. The purpose was to use the r parameter
as a tracer of variability for short-period (i.e., intranight) variability.

To search for long–period variability, we introduced a second parameter, more sensitive to
the night–to–night variations.
We calculated the mean magnitude Vi and the standard deviation σi on each night, and after that we calculated the parameter s defined as:

s=log10ΔV¯σ

where ΔV is the peak–to–peak difference
and ¯σ is the mean of the σi over all nights.

To test the capability of the r and s parameters to detect variable stars,
we prepared a sample containing two types of light curves:
7722 artificial constant light curves (see Montalto et al., (2007)
for details) and 70 light curves of already known variable stars which
are included in our CFHT field.
In Fig. 2 we plot r vs. s for the light curves
of constant stars (small points) and of variable stars (large points).
The variable stars are substantially apart from the constant stars and
most have r≳−1. The variable stars with r≲−1
and superposed on constant stars are mostly EA–type stars
or irregular stars (e.g., cataclysmic variables).
Among variables (i.e., large dots in Fig. 2), the stars with small s
have short periods (P≤0.50 d), while stars with large s have long periods.
Therefore, we can conclude that the combination of the r and s parameters
is a good tracer of variability.

To detect the variable stars in our sample of ∼82,000 light curves we first
selected in an automatic way all the stars with r≥−2.0, according to
the test described above. We thereby reduced the huge initial sample to ∼6,500 stars.
After the calculation of the amplitude spectrum of their
time series, we adopted as a second selection criterion
a signal–to–noise ratio (S/N) greater than 4.0 around the highest peak in the
amplitude spectrum. This procedure allowed us to reduce our sample to ∼900
stars, i.e., 1.1% of the whole initial sample.
Further checks have been made by examining the light curves of a random
sample of stars with r<−2.0, large s and 3.5<S/N<4.0, but we did not
find any additional variables.

Our approach allowed us to detected hundreds of stars showing peaks in their
power spectra at f=1.00 cd−1, at f≤0.05 cd−1, or
at f=0.6 cd−1.
The first two spurious periodicities are common and can be ascribed to
small misalignments in the mean magnitudes from one night to the next
or recurrent drifts (caused by small color effects, for example) in the
intranight light curves. We suggest that the latter one is probably a
photometric artefact occurring in some particular cases of blended stars,
or stars close to CCD edges, or bad pixels.
They have been considered as not reliable enough to infer a physical
light variability. In our opinion, only the combination of automatic
procedures and visual inspection allowed us to identify the three classes
(P=1.00 d, P=1.6 d, P≫10 d) of spurious variables in the
huge number of ∼82,000 light curves. In
particular, we note that the
identification of the whole sample of eclipsing binaries has been confirmed by the
application of the box fitting technique (BLS, Kòvacs et al. (2002)),
used by Montalto et al. ((2007)) to detect planetary transits.

At the end of the variable star identification, we were left with 330
cases to be characterized. Since we rejected about 2/3 of the
sample selected by means of the r,s parameters, we are confident
we have not applied overly strict constraints in the candidate selection.

Among the 81 known variable stars that we have observed,
not all of them display variability in our sample:
4 stars (V10, V18, V21, V32) are previously classified as long-period
detached eclipsing variables and we did not observed eclipses.
We are not able to confirm the period of 15.24 days for V68 (M03),
likely because of our shorter time baseline and the small
amplitude of this variable (about 0.003 mag in V–band, M03).
Finally, we cannot confirm the variability
of six stars (V20, V79, V84, V98, V99, V116) and of the seven suspected variables
found by H05, since our data do not show any trace of variability.

Among the sample of the stars missing from the CFHT field,
we identified 22 stars in the Loiano and SPM data sets
(V6, V13, V19, V20, V33, V45, V54, V56≡V96, V65, V66,
V67, V70, V71, V73, V74, V76≡V85, V77, V78, V81, V97, V106 and V113).
However, owing to the smaller signal–to–noise ratio (S/N),
the small number of datapoints and (in the case of the Loiano data)
the limited survey time, we could only confirm the variability
of stars V56≡V96, V66 and V76≡V85.

Throughout this paper we use the existing names for the already known variables;
to identify the new ones discovered in our survey we used
the five–digit number assigned by the DAOPHOT package followed by the number
of the chip which the star belongs to. Accurate astrometry is provided to identify the stars
on the sky. Moreover, all light curves of the variables
will be available on CDS.

The CFHT measurements are quite precise, thus the light curves
are generally very well defined for P<4 d. On the other
hand, the periods and the shapes are uncertain for P>4 d,
since the observations only covered 2.5 cycles or less.
We refer to Montalto et al. ((2007)) for a full description of the photometric
errors. In order to evaluate the precision in the study of the variable stars,
we calculated the standard deviations of the Fourier least-squares fits (truncated
at the last significant term for the given star) for the 138 light curves having
very good phase coverage.
The precision was found to be better than 0.010 mag in 73 cases (53%), and better than 0.020 mag in
a total of 122 cases (88%), as expected for stars ranging from V∼16.0 to V∼22.5.
The discussion based is mostly on the CFHT data, which are by far the most numerous, precise and
homogeneous; however, for some variables we have used data from Loiano and SPM in a very profitable way.
As an example, only the longitude spread of the three observatories allowed us
to derive the periods of the eclipsing binaries 00645_10, V107, V12, V109
and of the rotational variable 03079_9.

To proceed in the definition of the variable star content of NGC 6791 and its surrounding
field, we calculated
the power spectra of the data for all the 330 candidate variables
by using the least-squares iterative sine-wave search (Vanicek, (1971)) and the Phase
Dispersion Minimization (Stellingwerf, (1978)) methods.
Differences have been examined and resolved. The separation
into different classes of variable stars has been made on the basis of the light
curve parameters (period, amplitude, Fourier coefficients) and standard photometric
values (V, B−V, V−I), when available.
The period estimates have been refined by means of a least–squares procedure
(MTRAP, Carpino (1987)) and appropriate error bars have also been
calculated. At the end of the process we get
six pulsating stars with P<0.6 d, three irregular variables, three cataclysmic variables (CVs), 31 detached or semi–detached
eclipsing binaries, 29 contact binaries, 90 rotational variables, 167 stars showing
clear night-to-night variability on
timescales too long for periods to be determined over our 9.2–d baseline.
We adopt preliminary membership probabilities based on proper motion measurements
kindly provided to us by K. Cudworth (private communication) for 35 stars.
Moreover, for three new variable stars we adopted membership probabilities based on proper
motions performed by Bedin et al. ((2006)) (hereafter B06, see Figure 3).

For the other stars, we consider their position in color–magnitude diagrams (CMDs),
and their distance from the center of the cluster to infer whether they belong
to the cluster (for EW–Type stars we also utilize the P-L-C relation of Rucinski ((2003)).
Toward this end, we plotted the radial distribution of all stars in Fig. 4. We see that at a distance of ∼10′
from the center of the cluster, the stellar density becomes near constant
(about 21 star/arcmin2). Thus, we adopt the value of 10′ as
the external limit of the cluster and we consider “likely non-members” the variables
located farther from the cluster center.

Figure 4: Stellar density ρ (number of stars per square arcminute)
as a function of the distance from the center. The straight line represents the
mean stellar density at distances greater than 10′.

4.1 Pulsating variables

The main characteristics of our variables are listed in Tab. 3
and their light curves are shown in Fig. 5. The classification as
High–Amplitude Delta Sct (HADS), SX Phe, RRc or RRab stars
is based on the parameters of the Fourier decomposition
(Poretti, (2001)). In all cases, the ϕ21 Fourier parameters
are on the progressions described by the different classes.
We note that our period for V123
is quite different from that given by H05 (0.107 d).
Error bars on the periods are in the range 1–6⋅10−5 d.

Both RR Lyr variables are too faint to belong to NGC 6791.
Since they have V=17.21 (03653_3) and V=18.28 (00345_1),
their distance moduli greatly exceed that of the cluster.

This is also true for the very faint and short-period stars
00311_7 (V=23.17) and 00224_10 (V=21.72);
therefore, it is more likely that they are Pop. II stars.
On the other hand, using the P−L relation given by McNamara ((2000)), we get
distance moduli of 14.50 and 13.78, respectively, for V123 and 01497_12.
These distance moduli
and the distance from the cluster center (12′ and 22′, respectively)
suggest that they do not belong to the cluster, though they are not very far from it.
Therefore, they are probably Pop. I
stars and hence High Amplitude δ Scuti stars.

Moreover, there are several variables whose light curves
are very similar to those of Cepheid variables;
the Fourier decomposition of some light curves (in particular the
large amplitude ones, i.e., 00913_5, 01659_8, V46 and 01431_10,
but also 01606_11, 02285_10, 00122_4 and 03056_3) yields
parameters typical for Cepheid light curves. However, most of these variables are quite
faint and the Period–Luminosity relation for Cepheids (Tammann et al., (2003))
yields distances in the range 39-171 Kpc.
It is difficult to say whether these stars are nearby rotational
variables (see below) in the Milky Way or very distant pulsating variables. For our
present purposes, these stars have been included among the rotational variables listed
in the Appendix.

The puzzling nature of all these apparently distant stars (i.e., the Cepheid-like ones, the
RR Lyr and the faint SX Phe variables discussed above)
deserves further investigation by means of spectroscopic and/or kinematic data.

4.2 Irregular variables

Table 3 also lists three irregular variables: these stars lie on the
middle Main Sequence and are all located less than 3′ from the cluster center; thus we suggest that they belong to the cluster.
V92 and V83 were previously defined as “periodic variables” by B03.
Indeed, we noticed fast variability in our light curves
(Fig. 6), but,
more noticeably, the mean magnitude is also changing from night to night.
The long periods given by M03 are not able to explain either the short- or the
longer-timescale variability; actually, we could not detect any periodic term.
We also detected no trace of periodicity in V93 (Fig. 6); we suspect
that the periods given by M05 and B03 are spurious, since they are close to 1.0 d (0.99 and 0.94 d,
respectively) and they could be produced by the irregular fluctuations.

We can conjecture that these variables are eruptive variables observed
in a quiescent phase, in which rapid and/or slow
changes with smaller amplitude can be observed; they resemble the case of V15
(see Sect. 4.3). We have no reliable indications about the membership probabilities.

4.3 Cataclysmic variables

As regards V15: M03 and M05 detected variability over the range
of 3 mag and observed outbursts of about 0.5-1.0 mag; from our side,
we could see a 0.15–mag variability in our light curves (Fig. 6),
corresponding to the quiescent phase. V15 is very probably a NGC 6971 member,
since the Cudworth proper-motion membership probability is very high (98%).

Both the position of the faint blue star 06289_9 in the two-colour diagram
and the shape of its
light curve (Figure 7) strongly suggest that this star could be a new cataclysmic variable
(U Gem-type, dwarf nova). Moreover, we know that this object is a cluster member
(see Figure 3).
The star shows an outburst of about 3 mag and, though we did not observe the entire brightening,
we would highlight that the magnitude was still increasing on the first night;
thus we are able to say that the maximum brightness was reached immediately after.

We can estimate the orbital period, Porb, and the
recurrence time, Tn, from the decay
time, τd=Δt/Δm [days mag−1] and the amplitude,
Δm (Warner, (1995), equations 3.5, 3.1, respectively).
Assuming for Δt and Δm the values 3.33±0.50 d and 2.87±0.31 mag
respectively, we find
Porb=2.54±1.41 h and Tn=13.9±10.6 d.
However, our light curve (Fig. 7) seems to rule out
Tn values shorter than 8 d.

The variable B8 shows a large-amplitude light curve (Fig. 7) over
a quite short 7 d time span. The cataclysmic nature of B8
has been confirmed spectroscopically by Kaluzny et al. ((1997)) who
also notes that B8 exhibits red V−I colour while in a low state.

Following the same procedure used for 06289_9 and assuming
τd=1.3±0.3 d mag−1 for B8,
we find Porb=2.97±1.63 h and Tn=11.4±8.5 d.
The Tn value is compatible with the 7 d periodicity (Fig. 7).
A membership probability is not available for B8.
However, using the equations 3.3 and 3.4 after Warner ((1995)), we obtain
MVmin=8.06±0.68 mag and MVmax=4.97±0.42 mag.
In turn, these values give two estimates for the distance modulus of B8, i.e.,
13.82 ± 0.68 mag and 14.20 ± 0.42 mag. We note that the first is in agreement with
the distance modulus of the cluster.
Kaluzny et al. ((1997)) assumed that B8 belongs to the cluster,
finding MVmax=5.2 mag and MVmin=7.6, i.e., values very similar to ours.
B8 is located at 4′ from the center, and we can only conclude that the
membership of this star is very probable.

Star

Type

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

Pulsating variables

V123

HADS

19.362064

37.666034

17.08

0.45

k

59.559

0.06026

0.14

01497_12

HADS

19.379083

37.812419

16.06

59.528

0.07227

0.40

00311_7

SXPhe

19.324628

37.716768

23.17

59.605

0.10443

0.10

00224_10

SXPhe

19.353639

37.710163

21.72

0.71

1.06

s

59.801

0.12261

0.20

03653_3

RRc

19.347147

37.992413

17.21

0.57

0.58

k

59.937

0.32654

0.39

00345_1

RRab

19.325082

37.964170

18.28

60.151

0.57866

0.72

Irregular variables

V92

IRR

19.350754

37.766876

18.10

0.91

k

0.10

V83

IRR

19.346220

37.737232

19.10

1.02

1.05

k

0.07

V93

IRR

19.351452

37.785687

18.12

0.98

1.03

s

0.04

Cataclysmic variables

V15(=B7)

CV

19.352057

37.799019

18.26

0.20

k

0.06

B8

CV

19.343262

37.747833

20.64

–0.23

0.78

k

2.27

06289_9

CV (?)

19.348976

37.770355

22.80

0.25

0.88

s

3.10

Table 3: Pulsating, irregular and cataclysmic variables. V is the minimum brightness for
CVs and irregular, the mean brightness for pulsating variables. T0 is the
time of maximum brightness for pulsating stars.
Hereafter, the labels “k” and “s” indicate that the B−V color
index is taken from Kaluzny & Rucinski ((1995) or Stetson et al. ((2003)), respectively.

Figure 7: Top: Light curves of B8 (CV star) and 06289_9 (candidate CV).
Bottom: positions in the two–colour diagram for two irregular
stars (V83 and V93), for the cataclysmic variable B8 when in a low state,
and for the new variable candidate 06289_9.

4.4 Contact binaries

Figure 8: The light curves of the contact binaries that are
likely members of NGC 6791. The case of 01434_3 (amplitude much larger than
0.75 mag) is also shown in the last panel.Figure 9: The m−M values calculated for contact binaries
by means of the Rucinski ((2003)) P-L-C relation plotted against the distance from
the cluster center. Triangles indicate the stars whose membership has been proposed by
M03, the filled circles the stars whose membership has been proposed by us, and the open circles the stars
that we suggest do not belong to NGC 6791.
The starred point indicates the star 09891_9 which does not belong to the cluster
on the basis of the proper motion (B06).
The (m−M)V value for the cluster (solid line) with an error bar of ±0.20 mag
(dashed lines) is also shown.

The simplest cases of eclipsing systems are the contact binaries
(also named W UMa systems); they show
short periods and continuous variability
and therefore can be easily recognized and classified. We
detected 29 of these variable stars; they have
P<0.40 days and very well defined light curves. The complete list and the light curves are reported in the Appendix.
Tab. LABEL:ewbel lists the stars likely belonging to NGC 6791 (see above);
their light curves are shown in Fig. 8.
The very short periods and the secondary minima occurring at ϕ≈0.5
indicate binaries with circular orbits, as is also the case for stars with small amplitudes (in 7 cases
we have amplitudes less than 0.20 mag: V3, V4, V5, V8, V23, V40 and 01441_8).
The average error bar on the period estimates is of the order of 4–5⋅10−5 d.

However, we note that the stellar surfaces
are not homogeneous since the maxima are often at different heights. Therefore, binarity and
activity are probably combined here.
In particular, the shape of the light curves of V4 (comparing RK96, M02 and our data)
and V7 (comparing K93 and our data) have changed a lot;
we suppose that stellar spots strongly modify the light curves.
Proximity effects are also responsible for
the large amplitudes observed for 01434_3 (Fig. 8, last panel) and 00766_5.
We also found different periods for V118 (0.306321 d) and V124 (0.320143 d) compared to H05.

As for membership, the probabilities provided by Cudworth are
78%, 98% and 98% for V3, V4 and V5, respectively. Indeed, they are very close
to the cluster center (4\aas@@fstack′5, 2\aas@@fstack′1 and 2\aas@@fstack′8, respectively).

We suggest that
01441_8, V118, V8, V117 and V7 are also contact binaries belonging to NGC 6791.
To further verify this hint, we calculated their distance by using the P-L-C relation given by Rucinski ((2003)); they
turn out to have distance moduli
(13.28, 13.28, 13.48, 13.28 and 13.18, respectively) very similar to that of the cluster
(13.35).

Moreover, these stars are located at similar angular distances from the cluster center
(6\aas@@fstack′2, 7\aas@@fstack′2, 7\aas@@fstack′1, 7\aas@@fstack′2 and 6\aas@@fstack′3, respectively).
Figure 9
shows how the distance modulus of the cluster is in better agreement
with those of the stars we proposed as cluster members than with those of the previously known members.
Their positions in the CMDs (Fig. 10, filled circles) are similar
to those of stars in the sample with V<7.5 whose parallaxes have been determinated by HIPPARCOS
(Rucinski, (2003)).
We also note that most of the cluster members are near the turnoff point.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Notes

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

01441_8

19.339422

37.778118

19.98

1.38

k

63.073

0.24544

0.07

likely memb.

V118

19.347500

37.651222

17.68

0.75

1.01

s

59.912

0.30623

0.70

likely memb.

V5

19.346258

37.813354

17.19

0.90

0.95

k

60.221

0.31274

0.05

member (98%)

V3

19.354380

37.769349

18.51

1.05

1.06

k

59.798

0.31764

0.09

member (78%)

V4

19.348396

37.806652

17.72

1.01

k

59.591

0.32568

0.10

member (98%)

V8

19.341938

37.865810

17.81

0.79

0.88

k

59.896

0.33406

0.10

likely memb.

V117

19.343433

37.665848

17.66

0.87

0.90

k

59.987

0.36644

0.38

likely memb.

V7

19.340271

37.821892

17.63

0.93

0.86

k

59.820

0.39174

0.31

likely memb.

Table 4: Coordinates and light curve parameters of the contact binaries (W UMa systems, EW)
belonging to NGC 6791. V is the brightness at maximum
and T0 is the time of the primary minimum.

4.5 Eclipsing variables

In the cases of detached or semi–detached eclipsing binaries the classification
and membership tasks are different from the case of
contact binaries.
Tab. LABEL:tabea lists the systems for which we could determine periods; their light curves
are shown in Fig. 11.
We still have short-period cases where we can reconstruct the complete light curve, as
for the classical examples of β Lyr variables (V29, 01558_5 and 00331_3).
V9 is a more complicated β Lyr system in which spots produce maxima with different
heights. Indeed, it has been classified as an RS CVn variable by
M05 and B03; they also observed a “shift of the modulation wave” from 1995 to 2002.

We note that our period for V119 is quite different from that given by H05
(0.1133 days); the new period makes this star an intermediate case between semi–detached and contact systems.
Error bars on the periods in Tab. LABEL:tabea are ∼10−4 d for P<1.0 d, ∼10−3 d for 1.0<P<2.0 d
and a bit larger for P>3.0 d.

Some variables show very sharp eclipses and out-of-eclipse variability due to different levels of
stellar activity
(05736_9, 00645_10, V109, 01393_1, V11 and V107; for the period of the latter star we prefer the longer of the two values given by M05).

In many cases we observed one eclipse only and we cannot give any value for
the period, unless it has been given in the previous studies, as for the
cluster member V80
(86% on the basis of the Cudworth membership probability).
We also note that the amplitude we observed in V80 is much larger than that
reported by B03.

To establish the membership of these eclipsing systems is not an easy task, since binary effects
should be taken into account when considering colors and magnitudes. However,
on the basis of the distance from the cluster center and their position
in the CMDs, we can argue that V60, 02461_8 (both single-event eclipsing
binaries), 05736_9, V29 and 00645_10
are very probable members. This hint is corroborated by
the membership probabilities for V60 and 02461_8, which are 91% and 88% respectively.

The special cases of V9 and B4 deserve attention. V9 is the binary closest
to the center and its membership probability is 82%.
However, it looks a very evolved object in the CMD; its period
(3.2 d) and activity (see above) are also more typical for a Main
Sequence star. Therefore, its membership is very doubtful.

The Cudworth membership probability for B4 is only 40%, but
in the CMDs B4 belongs to a little “clump” of very blue stars.
This location is in agreement with the results of Liebert et al. ((1994))
and therefore B4 is likely a blue extanded horizontal–branch star belonging to NGC 6791.
The star is classified by M02 and M03 (who consider it a non–member) as an
eclipsing binary, but we note that the light curve could also result from a rotational modulation.

Other possible members are: V107, 00331_3, V109 and
V11, considering that they are within 6\aas@@fstack′4 radius from the cluster center.
The location in the CMDs of the eclipsing binaries belonging to NGC 6791 is
shown in Fig. 10 (triangles).

Star

Type

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Notes

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

V119

EB

19.351961

37.916328

18.15

1.13

1.33

k

59.879

0.30197

0.15

member ?

V29

EB

19.354796

37.751386

20.00

1.23

1.61

k

69.012

0.43662

0.22

likely memb.

01558_5

EB

19.372697

37.953469

19.15

69.028

0.52910

0.28

likely non–memb.

01393_1

EA

19.329588

37.970392

21.23

59.326

0.58998

0.56

likely non–memb.

00331_3

EB

19.352367

37.864391

19.73

1.20

1.36

k

68.815

0.7347

0.13

member ?

V11

EA

19.342575

37.804802

19.38

0.96

1.22

k

67.875

0.8833

0.48

member ?

05736_9

EA

19.348484

37.721855

20.20

1.21

k

68.333

1.210

0.29

likely memb.

V12

EB

19.345259

37.849083

17.52

0.96

k

64.103

1.524

0.06

member (96%)

00645_10

EA

19.354692

37.710104

20.60

1.33

1.46

k

60.893

1.451

0.20

likely memb.

V9

EB

19.346634

37.777035

17.15

1.23

1.38

k

63.873:

3.2

>0.2

member (82%)

V107

EA

19.355068

37.761553

17.97

0.93

1.00

k

64.433

3.27

0.24

member ?

V109

EA

19.342716

37.793961

20.73

1.46

1.60

k

69.021

3.70

0.86

member ?

Table 5: Eclipsing variables with well defined light curves.
EA stands for a β Per system, EB for a β Lyr one.
V is the brightness at maximum
and T0 is the time of the primary minimum. Also B4, V60 and 02461_8, whose parameters are
reported in the Appendix, are possible cluster members.
The last column shows the Cudworth membership
probability (when available).

4.6 Rotational variables

We found 89 variables whose light curves
are characterized by small amplitude (usually less than 0.10 mag) and
continuous variability. It is difficult to ascribe such
variability to contact binaries
undergoing grazing eclipses, since they should be less numerous than those having
partial eclipses, since grazing eclipses occur only for a particular orientation
of the orbital plane.
Our hypothesis is that in most cases this variability results from spots
carried by the
stellar rotation; under this hypothesis, a large variety of light curves can be produced.
Of course, we cannot rule out that a small fraction of these light curves might be actually generated
by grazing eclipses.

The complete list of the rotational variables and their light curves is given in the Appendix.
Here we discuss some examples.
If the inclination of the rotational axis causes the progressive disappearance of the largest spots,
the light curve displays continuous variation, which could be
sine shaped in the simplest cases (a fraction of the spots is always visible; it can also produce
Cepheid–like variability, as in the 001606_1 case, Fig. 12), or with a standstill
(the hot or cold spots totally disappear; 00513_2 in Fig. 12) or,
more commonly, it can be distorted by other spots besides the
largest ones (00471_12 in Fig. 12).
In cases of very active stars, a secondary wave also occurs (01175_5 in Fig. 12).
Since the second wave often covers less than
half of the period, these rotational variables can be distinguished from eclipsing binaries;
we also note that the amplitude ratio between the first and second waves can be very different.

Also in the three cases
in which the full amplitude is larger than 0.10 mag (V2, 02006_1 and 07483_9) rotational
effects explain the observed features better than eclipses.
For example, the light curves of V2 (P=0.273 d) and 01298_5 (P=0.586 d; see Fig. 12) show
typical eclipsing binary behaviour,
but the amplitudes, the periods, and, mainly, the asymmetries are more typical
of a rotational effect.
The case of 02270_11 is different (Fig. 12). Its light curve is very similar to
that of a contact binary, but it does not repeat exactly, and unusual scatter is observed through the cycle.
We also note that this non-repetitive behaviour of the light curves, due to the spot activity, is the reason
why several variables stars show residual standard deviations higher than expected.

Our periods for V34, V37 and V38 are approximately half of those given by
M02, since these authors classified these variables as ellipsoidal ones; the large amplitudes
(0.18, 0.06 and 0.13 mag) are more in favour of a variability resulting from large spots, rather than
the purely geometrical effect of tidally distorted stars. We also note that V37 did not show any flare
activity similar to that reported by M02 during our survey.
We have also revised the classification of V16, considered an eclipsing binary by M02 and M03.

We count 33 rotational variables
in the 10′–circle (i.e., 0.105 star/arcmin2) centered on the
cluster, while we have 56 variables in the remaining 924–arcmin2 area (i.e., 0.061 star/arcmin2).
We have color indices (B−V and/or V−I) for 48 stars;
33 of them have a radial distance less than 10′ from the cluster center.
We can confirm the membership for 6 stars having proper motion
membership: V16, V38, V42, V48, V53 and 03079_9.
We have no photometric indices for V41; however, it is at only 2′ from the
cluster center
and its Cudworth probability membership is 77%. Therefore, we consider V41 a member.
For V14 we have the opposite situation because this star is at 1′ from the
cluster center and its positions in the CMDs agree very
well with a membership, but the proper motion measurements rule out that
it can be a cluster member
(0%) (see Figure 13, V14 is displayed as a starred dot).
As mentioned by M03, the positions of V17 in the CMDs are unusual.
Other variables located below the subgiant branch like V17 were found
in the open cluster M67 (Mathieu et al., (2003)) and in the globular cluster
47 Tuc (Albrow et al., (2003)). Probably these objects (named “red
stragglers” or “sub-subgiant branch stars”) are the result of
some kind of mass exchange between the members of a binary system.

Putting the rotational variables without proper motion measurements
on the CMDs we could
infer that 8 stars are located on or close to the MS
(represented with filled circles in Fig. 13); thus we
suggest that these 8 stars belong to the cluster as well.
Among the variables at greater distances, for three stars (01149_2, 01122_4
and 00513_2, all located between 11′ and 13′) the membership is
doubtful, since their position in the CMDs is unclear.
The other stars show apparent magnitudes and/or color indices too discrepant
to be considered active MS stars belonging to NGC 6791.

When considering the variables without color indices,
only two (V41 and 01874_2) are at less than 10′from the cluster center.
We know that V41 is a probable cluster member (membership probability 77%), but,
at the moment, we have no valid reason to consider the other star as a member.

Table LABEL:rotbel lists the rotational variables we suggest as cluster members. The
error bars on the period are ∼10−4 d for P<1.0 d, ∼10−3 d for 1.0<P<2.0 d,
∼10−2 d for 2.0<P<5.0 d; periods longer than 5.0 d are tentative.
Figure 13 shows the CMDs with the
rotational variables belonging to the cluster (Tab. LABEL:rotbel) clearly indicated.
We rejected as cluster members 16 stars out of 32 located within 10′
from the cluster center; i.e., we considered them to be stars of the Galactic field. We note that the
resulting density of the Galactic field (0.051 star/arcmin2) superimposed
on the cluster is in good agreement with that of the surrounding galactic disk field (0.061 star/arcmin2,
see above), especially considering that Poisson statistics supply uncertainties around ±0.01 on the
density values.

The stellar rotation and the activity level are both expected to be small
for single stars as old as NGC 6791.
Therefore
we suggest that the rotational variables belonging to the cluster are likely short–period binaries,
whose rotational velocity and activity level have been enhanced by the tidal synchronization.

Figure 12: The light curves of a small sample of rotational variables,
illustrating the growing importance of the second wave.

Figure 13: (V−I)−V and (B−V)−V diagrams for NGC 6791.
The rotational variables that we suggest may belong to the cluster
are indicated with filled circles. Triangles: stars belonging to the
cluster according to the Cudworth’s membership; starred point: V14, open
square: V17 (see text for details about these stars).

Star

Type

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Notes

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

04803_9

RO1

19.347698

37.796043

21.81

1.33

1.84

s

61.799

1.1034

0.17

member (B06)

V82

RO1

19.344366

37.793381

19.01

1.00

1.02

k

56.481

1.1568

0.04

likely memb.

06553_9

RO1

19.349134

37.672577

19.26

1.04

1.13

s

61.421

1.3485

0.08

likely memb.

01724_9

RO1

19.344957

37.785362

20.73

1.29

1.69

s

64.410

1.6130

0.17

likely memb.

V38

RO1

19.351021

37.768288

18.82

0.96

k

55.630

1.96

0.13

member (92%)

03079_9

RO1

19.346190

37.754753

19.23

1.14

1.26

k

66.630

2.640

0.07

member (93%)

V14

RO1

19.347687

37.756874

18.58

0.93

1.05

k

55.933

5.45

0.05

non–member (0%)

V48

RO1

19.352076

37.718506

17.51

0.88

k

65.223

5.65

0.09

member (96%)

V17

RO1

19.344135

37.817928

17.92

1.20

1.28

k

63.211

6.523

0.04

member (88%)

V51

RO1

19.353382

37.748795

19.94

1.22

1.21

k

63.624

6.72

0.09

likely memb.

V52

RO1

19.355795

37.771935

17.49

0.88

0.88

k

64.345

7.06

0.03

likely memb.

V53

RO1

19.350233

37.743187

18.72

0.89

0.93

k

69.294

7.47

0.04

member (86%)

00436_3

RO2

19.352205

37.878635

18.92

0.92

1.08

k

60.018

0.26601

0.04

likely memb.

07483_9

RO2

19.349997

37.746311

21.28

1.32

1.70

s

60.465

0.4375

0.17

likely memb.

V41

RO2

19.347492

37.806892

19.09

60.000

0.4798

0.07

member (77%)

V42

RO2

19.350058

37.714867

19.51

1.05

1.16

k

60.323

0.5068

0.10

member (92%)

V16

RO2

19.352108

37.802662

17.79

0.93

1.01

k

67.713

2.182

0.03

member (96%)

Table 6: Rotational variables belonging to the cluster. V is the mean brightness value.
T0 indicates the time of the maximum brightness.
The last column shows the membership
probability (when available) or our photometric membership. The two
uncertain cases (V41 and V14) are also listed (see text).

4.7 Long-period variables

We detected numerous stars having different mean magnitudes on the different nights.
Their behaviours are more diversified than those of the stars we considered
as spurious on the basis of their close similarities.
The resulting power spectra are dominated by terms at very low frequencies, corresponding
to periods often much longer than 10 d. These periods cannot be evaluated in a precise
way, being comparable or, more frequently, longer than our time baseline. Therefore,
we can only argue that these stars are variables, either in a periodic or in an
irregular way. Since we detected many spotted stars, it is quite obvious to think that
most of these long-period variables are spotted stars having a rotational periods longer than 10 d.
The mean amplitude of these stars is about 0.02 mag, except for 5 stars whose amplitude
exceeds 0.1 mag.

Among the long-period variables, we used the Cudworth probabilities
to establish the membership of 18 stars.
In order to roughly estimate the membership of the remaining
long-period variables we checked their locations in the CMDs,
in the cases where at least one color is available. We suggest that
5 stars are likely members of NGC 6791: 02138_8, 01610_9, 04392_3, V75 and
02268_10 (see Figure 14). They lie along the MS or the red-giant branch
and, furthermore, they are all located at
distances smaller than 8\aas@@fstack′5, from the cluster center.
Looking at the position of the variable V76 ≡ V85 (memberships: 97%) in both
CMDs, we suggest
that this star could be similar to the “sub-subgiant branch” star V17.
In Figure 15 we show its light curve and those of the
5 stars that we suspect to belong to the cluster.
Table LABEL:lptab lists the long-period variables we suggest as
cluster members; the entire sample is listed in the Appendix.

Figure 14: (B−V)−V and (V−I)−V diagrams for NGC 6791. Filled circles:
long–period variables that we suggest belong to the cluster. Filled triangles:
long–period variables that belong to the cluster (membership probability
higher than 76%.)Figure 15: Light curve of the suspect “red straggler”
V76 ≡ V85 and the five stars that we suggest may
belong to the cluster.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

Ampl.

Notes

Distance

[mag]

[mag]

[mag]

[mag]

arcmin

02138_8

19.341864

37.749653

19.68

1.12

1.18

k

0.06

likely memb.

4.6

02444_8

19.342766

37.810604

18.34

0.93

1.00

k

0.02

member (78%)

4.4

00510_9

19.343704

37.796719

18.67

0.94

0.98

k

0.03

member (83%)

3.4

01610_9

19.344818

37.740486

19.09

1.01

1.05

k

0.02

likely memb.

3.0

V94

19.345139

37.743549

17.54

0.88

0.92

k

0.03

member (90%)

2.7

V95

19.345295

37.792412

19.16

1.03

1.10

k

0.07

member (93%)

2.3

V56(=V96)

19.345908

37.763525

17.01

0.95

0.97

k

0.04

member (98%)

1.6

04392_3

19.345982

37.870571

17.90

0.88

0.92

k

0.02

likely memb.

6.1

V75

19.346651

37.766308

17.38

0.94

0.98

s

0.01

likely memb.

1.0

04133_9

19.347109

37.777020

18.47

0.94

0.98

k

0.04

member (98%)

0.7

V76(=V85)

19.347192

37.764169

18.19

1.03

1.15

k

0.11

member (97%)

0.8

V86

19.347258

37.808815

19.44

1.06

1.14

k

0.03

member (83%)

2.3

V87

19.347996

37.749668

18.12

0.91

0.93

k

0.03

member (98%)

1.3

05740_9

19.348534

37.808022

17.96

0.93

k

0.03

member (95%)

2.2

06725_9

19.349329

37.724495

17.77

0.91

k

0.02

member (91%)

3.0

06796_9

19.349415

37.769268

18.46

0.92

1.04

k

0.03

member (92%)

1.0

V90

19.349686

37.746449

18.11

0.86

0.94

k

0.01

member (94%)

1.9

07680_9

19.350193

37.718224

18.32

0.89

0.97

k

0.03

member (98%)

3.5

V31

19.350683

37.785912

17.12

1.00

1.02

k

0.01

member (97%)

2.1

09376_9

19.351952

37.831886

18.21

1.00

1.02

k

0.01

member (92%)

4.6

09611_9

19.352139

37.773365

17.97

0.85

0.91

k

0.01

member (76%)

2.9

V58

19.354042

37.801240

17.52

0.89

0.94

k

0.05

member (87%)

4.6

02268_10

19.359475

37.731544

18.59

0.95

0.99

k

0.02

likely memb.

8.5

Table 7: Long period variable stars that are likely members
of NGC 6791 (ordered by increasing right ascension). The column 9 shows the membership probability (when available) or our photometric membership.

Our wide-field survey of NGC 6791 for the planetary-transit search allowed us to
discover 260 new variable stars. When considering the membership probabilities given
by Cudworth and B06, 13 of them belong to the cluster and one star (09831_9)
is not member.
On the basis of the distances from the cluster center and the positions
in the CMDs, we suggest that another 11 stars are
likely members, for 22 stars the membership is doubtful, and 137 stars are likely non-members.
No photometric or kinematic data are available for 76 stars.

The variable star content of the cluster is very similar to that of the surrounding Galactic environment:
in both samples we find rotational variables, contact and eclipsing systems. Contact
binaries and rotational variables belonging to the cluster have the same
characteristics as those located in the surrounding Galactic field. No evidence of
pulsating variables has been found in NGC 6791, but this is not surprising, since
it is a very evolved cluster and stars located in the instability strip or hotter
pulsators have already left the MS.

The discovery of the new cataclysmic variable 06289_9 in addition to B8 and V15 adds another peculiarity to NGC 6791, making it unusual among
the open clusters.

Acknowledgements.

We are grateful to Kyle Cudworth kindly providing us with preliminary cluster
membership probabilities.
We also acknowledge Prof. Antonio Bianchini for his suggestions about the characteristics
of the candidate cataclysmic variable and Giovanni Carraro for his useful comments.
We thank the referee, Dr. J. Kaluzny, for his detailed report and useful comments.
This work was funded by COFIN 2004
“From stars to planets: accretion, disk evolution and
planet formation” by MIUR and by PRIN 2006
“From disk to planetary systems: understanding the origin
and demographics of solar and extrasolar planetary systems”
by INAF.

Appendix A List of identified variables

This Appendix includes the full list of the identified variables, separated according to our classification:

Into the tables, for each star we give the name (a five–digit number followed by the chip number which
the star belongs), coordinates, photometric data
(always the V mag, B−V color when available), informations about the variability
(T0, period, amplitude), distance from the center (in arcmin)
and finally the numerical value of the Cudworth’s membership probability (reported in the column ’Memb.’).

In most cases, when membership probabilities were not available, in the same column
the label “m” means that we retain the star belonging to the cluster,
while ’m?’ and “nm” mean “uncertain membership” and “likely non–member” respectively.
The label “nd1” means that no photometric data are available to advance hypothesis about the membership,
but the star is located nearer than 10′ from the center of the cluster.
Finally “nd2” means that no photometric data are available and the star is located
further than 10′ from the center; in this case we strongly suggest that the star does not
belongs to the cluster.

Star

Type

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

V123

HADS

19.362064

37.666034

17.08

0.45

k

59.559

0.06026

0.14

nm

11.8

01497_12

HADS

19.379083

37.812419

16.06

59.528

0.07227

0.40

nd2

22.2

00311_7

SXPhe

19.324628

37.716768

23.17

59.605

0.10443

0.10

nd2

17.0

00224_10

SXPhe

19.353639

37.710163

21.72

0.71

1.06

s

59.801

0.12261

0.20

nm

5.4

03653_3

RRc

19.347147

37.992413

17.21

0.57

0.58

k

59.937

0.32654

0.39

nm

13.3

00345_1

RRab

19.325082

37.964170

18.28

60.151

0.57866

0.72

nd2

20.0

V92

IRR

19.350754

37.766876

18.10

0.91

k

0.10

m

1.9

V83

IRR

19.346220

37.737232

19.10

1.02

1.05

k

0.07

m

2.4

V93

IRR

19.351452

37.785687

18.12

0.98

1.03

s

0.04

m

2.6

V15(=B7)

CV

19.352057

37.799019

18.26

0.20

k

0.06

98

3.3

B8

CV

19.343262

37.747833

20.64

–0.23

0.78

k

2.27

m

3.7

06289_9

CV

19.348976

37.770355

22.80

0.25

0.88

s

3.10

m (B06)

0.7

Table 8: Pulsating, irregular and cataclysmic variables. V is the minimum brightness for
CVs and irregular, the mean brightness for pulsating variables. T0 is the
time of maximum brightness for pulsating stars.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

V122

19.360729

37.641436

20.92

59.614

0.22883

0.58

nd2

11.9

V115

19.330646

37.975902

20.70

59.473

0.23636

0.24

nd2

17.4

01407_8

19.339256

37.701576

21.52

0.64

1.25

k

59.447

0.24155

0.82

nm

7.5

01150_4

19.357227

37.962177

18.58

1.07

0.93

k

59.455

0.24510

0.27

nm

13.2

01441_8

19.339422

37.778118

19.98

1.38

k

63.073

0.24544

0.07

m

6.2

00144_2

19.334044

38.030701

19.19

59.457

0.24780

0.77

nd2

18.5

01670_10

19.357625

37.681442

16.64

1.14

1.24

k

59.729

0.25807

0.49

nm

8.7

V121

19.358063

37.932346

17.24

0.81

0.84

k

59.619

0.26742

0.71

nm

12.0

02291_11

19.371624

37.795464

19.15

59.582

0.26774

0.29

nd2

16.8

V23

19.338614

37.787781

16.92

1.04

1.23

k

59.915

0.27180

0.07

nm

6.8

V25

19.328426

37.713237

18.50

59.772

0.27730

0.56

nd2

14.4

00665_12

19.375697

37.713244

18.89

59.472

0.28369

0.41

nd2

20.0

09831_9

19.352356

37.780907

20.55

1.09

1.19

s

59.662

0.29488

0.3

nm (B06)

3.1

01434_3

19.350643

37.985512

22.10

59.831

0.30581

0.97

nd2

13.0

V118

19.347500

37.651222

17.68

0.75

1.01

s

59.912

0.30623

0.70

m

7.2

00721_11

19.365737

37.713858

15.53

59.491

0.31008

0.26

nd2

13.1

01701_2

19.341944

38.017998

18.72

59.534

0.31201

0.51

nd2

15.4

V5

19.346258

37.813354

17.19

0.90

0.95

k

60.221

0.31274

0.05

98

2.8

V3

19.354380

37.769349

18.51

1.05

1.06

k

59.798

0.31764

0.09

78

4.5

02030_4

19.353487

38.009422

19.04

1.19

1.42

k

59.614

0.31797

0.33

nm

14.8

V124

19.365150

37.681544

17.62

0.70

1.07

k

59.855

0.32014

0.58

nm

13.3

00766_5

19.367585

37.943904

22.31

59.466

0.32363

0.78

nd2

17.3

V4

19.348396

37.806652

17.72

1.01

k

59.591

0.32568

0.10

98

2.1

V27

19.336275

37.648720

18.47

0.82

1.29

k

59.763

0.33170

0.84

nm

11.2

V8

19.341938

37.865810

17.81

0.79

0.88

k

59.896

0.33406

0.10

m

7.1

V101

19.351563

37.640388

19.94

0.56

k

59.798

0.33480

0.29

nm

8.3

V117

19.343433

37.665848

17.66

0.87

0.90

k

59.987

0.36644

0.38

m

7.2

V7

19.340271

37.821892

17.63

0.93

0.86

k

59.820

0.39174

0.31

m

6.3

V40

19.327495

37.616839

19.67

60.101

0.39750

0.16

nd2

17.3

Table 9: Contact binaries; V is the brightness at maximum
and T0 is the
time of the primary minimum.Figure 16: Contact variables.

Star

Type

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

Notes

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

V119

EB

19.351961

37.916328

18.15

1.13

1.33

k

59.879

0.30197

0.15

m?

9.1

B4

E:

19.353589

37.764290

17.87

–0.13

–0.15

k

54.788

0.39841

0.02

40

4.0

V29

EB

19.354796

37.751386

20.00

1.23

1.61

k

69.012

0.43662

0.22

m

4.9

Light curve distortion

at maximum light

01558_5

EB

19.372697

37.953469

19.15

69.028

0.52910

0.28

nd2

20.6

01393_1

EA

19.329588

37.970392

21.23

59.326

0.58998

0.56

nd2

17.7

00331_3

EB

19.352367

37.864391

19.73

1.20

1.36

k

68.815

0.7347

0.13

m?

6.4

V11

EA

19.342575

37.804802

19.38

0.96

1.22

k

67.875

0.8833

0.48

m?

4.4

05736_9

EA

19.348484

37.721855

20.20

1.21

k

68.333

1.210

0.29

m

3.0

V12

EB

19.345259

37.849083

17.52

0.96

k

64.103

1.524

0.06

96

5.1

00645_10

EA

19.354692

37.710104

20.60

1.33

1.46

k

60.893

1.451

0.20

m

6.0

V9

EB

19.346634

37.777035

17.15

1.23

1.38

k

63.873

3.2

0.20

82

1.1

V107

EA

19.355068

37.761553

17.97

0.93

1.00

k

64.433

3.27

0.24

m?

5.0

Minima at the very

beginning of the night.

V109

EA

19.342716

37.793961

20.73

1.46

1.60

k

69.021

3.70

0.86

m?

4.0

00219_11

EA

19.364048

37.827507

17.94

0.92

0.87

k

67.913

0.52

nm

11.9

00663_4

EA

19.359652

37.894062

17.49

0.79

0.83

k

65.003

0.49

nm

11.0

00671_2

EA

19.336983

37.903919

18.46

0.70

0.91

k

64.968

0.07

nm

11.2

00828_5

EA

19.367917

37.885330

21.28

64.979

0.38

nd2

15.7

00938_2

EA

19.338285

37.861633

20.57

1.20

1.80

k

67.867

0.60

nm

8.8

00997_10

EA

19.355692

37.799655

19.58

0.76

0.83

k

68.020

0.20

nm

5.7

01709_1

EA

19.330890

37.932268

18.04

64.818

0.32

nd2

15.5

01731_10

EA

19.357813

37.672819

19.27

0.67

0.80

k

64.783

0.34

nm

9.1

Minimum at the very

beginning of the night.

01780_8

EA

19.340677

37.655354

22.19

2.25

k

68.969

0.66

nm

8.7

02461_8

EA

19.342779

37.741798

19.34

1.06

1.15

k

60.968

0.11

88

4.2

01740_7

EA

19.330623

37.638774

21.30

69.007

0.33

nd2

14.8

Maybe another minimum

at 64.40

02045_12

EA

19.381420

37.712211

17.16

68.030

0.26

nd2

24.0

Other minimum at 63.39

02241_11

EA

19.371472

37.827819

19.21

68.823

0.53

nd2

17.0

Maybe another minimum

at 63.50

00346_5

EA

19.365356

37.929481

20.16

65.014

0.17

nd2

15.5

Other minimum at

at 68.410. Short in time.

00631_12

EA

19.375473

37.649140

17.92

68.753

0.30

nd2

20.9

Minimum at the very

beginning of the night.

01511_10

EA

19.357145

37.689907

19.74

1.45

1.86

k

0.50

nm

8.1

Two Minima at night extrema.

V60

EA

19.350189

37.762493

18.68

0.96

k

67.951

0.39

91

1.6

V80

EA

19.351799

37.791061

17.90

0.94

k

67.607

4.631

0.10

86

2.9

Shallow eclipse ?

V108

EA

19.352606

37.823467

21.15

1.27

1.90

k

69.080

0.86

nm

4.5

Table 10: Eclipsing variables. V is the brightness at maximum
and T0 is the time of the primary minimum.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

02268_12

19.382495

37.798839

17.42

60.323

0.30910

0.02

nd2

24.6

02418_3

19.349085

38.016541

21.68

59.901

0.36498

0.12

nd2

14.7

00513_2

19.336012

37.940765

20.12

1.18

1.51

k

60.786

0.45272

0.08

m?

13.3

02292_10

19.359535

37.710207

16.24

1.11

1.25

k

61.298

0.46371

0.06

nm

9.0

01497_11

19.368601

37.770512

18.58

61.737

0.56508

0.01

nd2

14.6

01776_4

19.354509

37.935883

19.70

0.99

1.16

k

61.154

0.68029

0.06

nm

10.9

00301_5

19.365041

37.906284

22.10

62.833

0.70170

0.21

nd2

14.5

00088_8

19.333437

37.744888

21.92

65.464

0.70594

0.11

nd2

10.5

V43

19.344337

37.641777

19.58

1.62

2.97

k

55.976

0.75759

0.08

nm

8.2

00554_8

19.335732

37.664570

21.32

1.22

1.48

k

65.543

0.821

0.13

nm

10.9

00612_10

19.354604

37.729215

22.97

0.79

2.42

s

68.050

0.91581

0.24

m?

5.3

01105_12

19.377359

37.737573

19.31

62.539

0.91746

0.04

nd2

21.0

00913_5

19.368442

37.859339

20.89

62.405

1.06386

0.24

nd2

15.4

04803_9

19.347698

37.796043

21.81

1.33

1.84

s

61.799

1.1034

0.17

m (B06)

1.5

01606_11

19.368978

37.736585

20.36

62.390

1.12360

0.10

nd2

15.0

V82

19.344366

37.793381

19.01

1.00

1.02

k

56.481

1.1568

0.04

m

2.9

V34

19.335878

37.736183

19.30

1.16

1.41

k

54.955

1.20486

0.18

nm

8.9

05302_3

19.344669

37.968491

18.90

63.224

1.3334

0.15

nd2

12.1

06553_9

19.349134

37.672577

19.26

1.04

1.13

s

61.421

1.3485

0.08

m

6.0

00471_12

19.374883

37.674950

19.35

61.900

1.3513

0.06

nd2

20.0

00110_5

19.363887

38.001389

21.69

62.103

1.4085

0.08

nd2

17.8

01874_2

19.342730

37.912987

21.96

64.944

1.5503

0.14

nd1

9.3

V111

19.346970

37.812141

20.67

1.46

1.66

s

61.673

1.5626

0.15

nm

2.5

V37

19.355072

37.852001

19.58

1.65

2.48

k

55.721

1.6130

0.06

nm

6.9

01724_9

19.344957

37.785362

20.73

1.29

1.69

s

64.410

1.6130

0.17

m

2.4

02285_10

19.359424

37.607155

19.26

1.34

1.57

k

63.495

1.6668

0.08

nm

12.8

01189_11

19.367513

37.809413

20.46

64.500

1.7242

0.10

nd2

14.0

00016_5

19.363396

37.997513

18.68

1.54

2.52

k

63.157

1.7858

0.07

nm

17.4

00732_12

19.375889

37.717569

19.39

61.992

1.852

0.04

nd2

20.1

00771_11

19.365949

37.766208

19.52

62.492

1.852

0.09

nd2

12.7

00676_1

19.326459

37.929277

20.54

65.481

1.887

0.11

nd2

18.0

V38

19.351021

37.768288

18.82

0.96

k

55.630

1.96

0.13

92

2.1

02103_7

19.332028

37.696796

19.57

1.65

k

60.891

2.041

0.05

nm

12.3

00575_12

19.375449

37.792459

19.63

65.359

2.214

0.02

nd2

19.5

01914_1

19.331830

37.878855

17.71

0.73

k

62.358

2.222

0.03

nm

13.2

03838_3

19.346848

37.964615

19.45

0.91

1.05

k

64.159

2.261

0.04

nm

11.6

V44

19.326970

37.694771

18.38

58.310

2.285

0.02

nd2

15.7

00321_1

19.324957

37.905996

19.49

65.394

2.326

0.04

nd2

18.3

00810_5

19.367793

37.865903

18.17

67.424

2.564

0.05

nd2

15.1

03079_9

19.346190

37.754753

19.23

1.14

1.26

k

66.630

2.640

0.07

93

1.7

01821_12

19.380347

37.604033

20.13

70.829

2.647

0.06

nd2

25.1

01309_11

19.367871

37.748052

20.81

61.125

2.692

0.05

nd2

14.2

01956_12

19.380972

37.626492

21.39

63.833

2.699

0.06

nd2

25.0

00815_1

19.327108

37.861623

19.75

63.358

2.836

0.05

nd2

15.8

01659_8

19.340244

37.694355

21.27

1.51

1.85

k

64.446

2.840

0.17

nm

7.2

00293_11

19.364252

37.703417

15.82

0.80

0.88

k

63.606

2.941

0.05

nm

12.2

00215_5

19.364447

37.898928

22.26

65.340

3.15

0.14

nd2

13.9

03209_10

19.362653

37.732028

18.61

1.54

2.57

k

66.016

3.17

0.06

nm

10.7

01313_1

19.329261

38.025661

21.27

62.466

3.704

0.10

nd2

20.3

00277_8

19.334366

37.776566

19.52

1.54

2.68

k

60.691

4.167

0.05

nm

9.7

00179_5

19.364283

38.002234

17.18

0.91

0.90

k

64.764

4.323

0.04

nm

18.0

03039_10

19.362130

37.815850

16.58

0.79

0.87

k

65.634

4.423

0.02

nm

10.4

01555_4

19.355373

37.961205

21.22

69.673

4.546

0.09

nd2

12.5

02614_11

19.372592

37.625244

17.22

70.152

4.763

0.04

nd2

19.6

01149_2

19.339287

37.966995

17.80

0.90

0.93

k

67.803

5.0

0.04

m?

13.3

02815_3

19.348427

37.967987

19.87

1.68

2.40

k

60.828

5.0

0.05

nm

11.8

V46

19.355272

37.798869

18.65

1.18

1.36

k

56.886

5.2

0.14

nm

5.4

00357_5

19.365449

37.996214

20.91

63.108

5.3

0.07

nd2

18.3

01484_7

19.329583

37.791249

20.30

1.63

k

67.924

5.3

0.03

nm

13.2

V14

19.347687

37.756874

18.58

0.93

1.05

k

55.933

5.45

0.05

0

0.9

V48

19.352076

37.718506

17.51

0.88

k

65.223

5.65

0.09

96

4.3

Continue …

Table 11: Rotational variables with a single–wave light curve. V is the mean brightness value.
T0 indicates the time of the maximum brightness.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

00615_7

19.325908

37.753712

20.59

59.885

5.882

0.14

nd2

15.8

V89

19.349068

37.776783

18.75

0.88

1.20

s

63.447

5.884

0.05

nm

0.8

00188_12

19.373720

37.632076

21.78

67.253

6.25

0.06

nd2

20.1

V17

19.344135

37.817928

17.92

1.20

1.28

k

63.211

6.523

0.04

88

3.9

01122_4

19.357346

37.914520

18.84

1.03

1.12

k

65.843

6.69

0.11

m?

10.8

03056_3

19.347979

37.869431

17.10

0.89

0.97

k

66.673

6.70

0.07

nm

5.9

V51

19.353382

37.748795

19.94

1.22

1.21

k

63.624

6.72

0.09

m

4.0

00640_10

19.354585

37.604724

17.97

0.68

0.77

k

66.173

6.8

0.03

nm

11.0

V52

19.355795

37.771935

17.49

0.88

0.88

k

64.345

7.06

0.03

m

5.5

V53

19.350233

37.743187

18.72

0.89

0.93

k

69.294

7.47

0.04

86

2.3

01431_10

19.357001

37.763810

17.72

1.33

1.45

k

67.953

7.64

0.26

nm

6.4

01616_11

19.369060

37.767818

17.26

69.157

7.70

0.05

nd2

14.9

01478_3

19.350523

37.862484

17.15

1.03

1.11

k

72.123

7.96

0.07

nm

5.7

05877_9

19.348616

37.767616

20.22

1.32

1.49

k

64.272

8.0

0.12

nm

0.5

Table 12: Continue from Table 11: other rotational variables with a single–wave light curve. V is the mean brightness value.
T0 indicates (one of) the times of maximum brightness.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

T0

Period

Ampl.

Memb.

Distance

[mag]

[mag]

[mag]

[HJD–2452400]

[d]

[mag]

[arcmin]

00436_3

19.352205

37.878635

18.92

0.92

1.08

k

60.018

0.26601

0.04

m

7.1

V2

19.354875

37.766689

19.74

0.93

1.21

k

59.712

0.27344

0.17

nm

4.9

02006_1

19.332258

38.043080

21.54

60.448

0.37500

0.19

nd2

19.8

01175_5

19.370209

37.998342

19.73

59.918

0.41481

0.09

nd2

20.8

00536_11

19.365067

37.716529

19.13

60.460

0.43740

0.03

nd2

12.6

07483_9

19.349997

37.746311

21.28

1.32

1.70

s

60.465

0.4375

0.17

m

2.1

V41

19.347492

37.806892

19.09

60.000

0.4798

0.07

77

2.2

V42

19.350058

37.714867

19.51

1.05

1.16

k

60.323

0.5068

0.10

92

3.7

01362_7

19.329000

37.662097

20.53

60.502

0.5560

0.08

nd2

15.1

02270_11

19.371548

37.794338

17.95

60.525

0.5679

0.05

nd2

16.8

01298_5

19.371044

38.002255

19.76

60.402

0.5859

0.06

nd2

21.4

V16

19.352108

37.802662

17.79

0.93

1.01

k

67.713

2.182

0.03

96

3.4

00568_2

19.336329

37.881542

18.52

60.007

2.704

0.08

nd2

10.6

00019_7

19.323382

37.710172

18.95

65.473

5.882

0.12

nd2

17.9

Table 13: Rotational variables with a double–wave light curve. V is the mean brightness value.T0 indicates (one of) the times of maximum brightness.Figure 17: Rotational variables with a single–wave light curve,
in some cases very distorted.Figure 18: Rotational variables with a single–wave light curve,
in some cases very distorted.Figure 19: Rotational variables with a single–wave (from V51 to 05877_9)
and a double–wave light curve.

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

Memb.

Distance

Star

α2000

δ2000

V

<B−V>

<V−I>

Ref.

Memb.

Distance

[mag]

[mag]

[mag]

[arcmin]

[mag]

[mag]

[mag]

[arcmin]

00091_1

19.323698

37.943716

19.16

nd2

20.2

V90

19.349686

37.746449

18.11

0.86

0.94

k

94

1.9

00143_1

19.323947

37.927971

20.11

nd2

19.5

02011_3

19.349693

37.958382

19.50

1.19

1.16

k

nm

11.3

00250_7

19.324384

37.779393

18.32

nd2

16.8

01908_3

19.349867

37.947132

19.29

1.05

1.09

k

m?

10.6

00326_7

19.324675

37.719342

17.99

nd2

16.9

V91

19.350151

37.811325

18.07

0.83

0.91

k

m?

2.8

00364_7

19.324832

37.798606

20.17

nd2

16.6

07680_9

19.350193

37.718224

18.32

0.89

0.97

k

98

3.5

00377_1

19.325260

38.018518

18.72

nd2

21.9

07914_9

19.350483

37.822048

18.64

1.12

1.27

s

m?

3.5

00466_7

19.325296

37.809032

14.65

nd2

16.3

V100

19.350498

37.761631

17.13

1.02

k

m?

1.8

00435_1

19.325525

37.990790

16.89

nd2

20.7

V31

19.350683

37.785912

17.12

1.00

1.02

k

97

2.1

00537_1

19.325956

38.059293

18.33

nd2

23.3

01344_3

19.350784

37.970558

18.17

1.33

1.48

k

nm

12.1

00552_1

19.325972

37.941670

18.10

nd2

18.7

V62

19.350847

37.731068

19.45

1.02

1.07

k

m?

3.1

00651_7

19.326084

37.647564

16.89

nd2

17.3

01252_3

19.350937

37.911869

19.85

1.55

2.66

k

nm

8.7

00819_7

19.326732

37.764538

18.02

nd2

15.2

08747_9

19.351194

37.651299

21.32

1.50

1.71

s

nm

7.6

00836_7

19.326803

37.684309

19.78

nd2

16.0

00990_3

19.351418

38.014648

17.29

nd2

14.8

00804_1

19.327102

38.039468

21.14

nd2

21.9

V110

19.351603

37.741802

17.75

0.71

0.76

k

25

3.1

00814_1

19.327140

38.035436

20.78

nd2

21.7

09376_9

19.351952

37.831886

18.21

1.00

1.02

k

92

4.6

00973_1

19.327784

37.996820

19.17

nd2

19.7

09611_9

19.352139

37.773365

17.97

0.85

0.91

k

76

2.9

01095_7

19.327905

37.726883

15.41

nd2

14.6

V66

19.352339

37.748669

15.95

1.29

1.39

k

m?

3.3

01145_1

19.328562

38.051636

20.12

nd2

21.8

00038_3

19.352835

37.851254

19.06

0.88

0.97

k

m?

5.9

01382_7

19.329091

37.812623

18.99

nd2

13.7

00176_10

19.353423

37.611797

17.90

1.39

1.59

k

nm

10.3

01536_7

19.329780

37.640689

17.85

0.91

k

nm

15.2

V58

19.354042

37.801240

17.52

0.89

0.94

k

87

4.6

01513_1

19.330106

37.876259

17.18

0.70

k

nm

14.2

00630_10

19.354660

37.738732

18.98

1.27

1.29

k

m?

5.1

01746_7

19.330667

37.812027

18.84

1.08

k

nm

12.6

00670_10

19.354823

37.806999

23.18

-0.40

0.54

s

m?

5.3

01829_7

19.330990

37.707912

15.20

1.31

k

nm

12.7

01536_4

19.355383

37.882149

17.21

1.18

1.29

k

nm

8.4

01873_1

19.331671

37.912256

19.41

0.98

k

nm

14.4

01415_4

19.355972

38.000843

17.60

1.50

1.92

k

nm

14.9

02096_7

19.332013

37.776243

16.79

1.05

k

nm

11.4

01169_10

19.356078

37.634936

15.34

0.88

1.02

k

nm

10.0

02126_7

19.332109

37.673400

19.20

1.38

k

nm

12.8

V55

19.356228

37.841698

16.12

1.48

1.88

k

nm

7.2

02004_1

19.332252

38.055218

19.85

nd2

20.4

01232_10

19.356296

37.664158

19.31

1.41

1.64

k

nm

8.7

02262_7

19.332626

37.658640

17.99

0.77

k

nm

12.9

01225_10

19.356349

37.770012

21.02

2.91

k

nm

5.9

V114

19.333338

37.812103

17.60

1.10

1.15

k

m?

10.7

01279_10

19.356519

37.757845

20.83

1.00

1.22

k

nm

6.1

00285_2

19.334742

38.038967

19.13

nd2

18.6

01210_4

19.356915

37.957123

17.69

0.75

0.86

k

nm

12.8

00404_8

19.335062

37.790737

18.68

0.69

k

nm

9.3

01417_10

19.356934

37.756828

17.03

1.11

1.17

k

nm

6.4

00386_2

19.335152

37.960213

21.51

nd2

14.6

01101_4

19.357428

37.882973

18.25

1.02

1.11

k

nm

9.4

00620_8

19.335981

37.656742

18.99

1.61

2.08

k

nm

11.0

01082_4

19.357555

37.938122

20.49

1.24

1.10

k

nm

12.1

00791_2

19.337513

38.014545

18.01

nd2

16.4

01070_4

19.357592

37.913498

17.53

1.49

2.15

k

nm

10.9

00907_2

19.338146

38.041290

15.62

nd2

17.6

01682_10

19.357705

37.729503

18.40

0.93

0.98

k

m?

7.3

01212_8

19.338499

37.721958

18.45

0.99

1.10

s

nm

7.4

01807_10

19.358104

37.721153

18.17

1.49

2.02

k

nm

7.8

01222_8

19.338552

37.737770

18.26

1.12

1.18

k

nm

7.1

00920_4

19.358349

37.962833

17.65

0.98

1.00

k

nm

13.6

01126_2

19.339148

37.937424

16.93

nd2

11.8

01885_10

19.358407

37.824782

19.23

0.83

0.88

k

nm

8.0

01122_2

19.339149

38.031670

18.55

nd2

16.8

02145_10

19.359033

37.664901

16.66

1.24

1.36

k

nm

10.1

01406_8

19.339247

37.695103

19.03

1.22

1.37

k

nm

7.8

02165_10

19.359100

37.668317

19.60

1.54

2.31

k

nm

10.0

V59

19.339304

37.806061

17.96

1.30

1.42

k

nm

6.6

02250_10

19.359370

37.663215

18.71

0.99

1.12

k

nm

10.4

01179_2

19.339432

37.995293

19.66

nd2

14.7

00717_4

19.359394

37.895435

18.02

1.28

1.42

k

nm

11.0

01622_8

19.340046

37.629841

18.09

1.42

1.64

k

nm

10.2

00718_4

19.359436

37.961086

20.26

1.44

1.67

k

nm

13.9

02022_8

19.341475

37.682644

18.58

1.27

1.44

k

nm

7.1

02268_10

19.359475

37.731544

18.59

0.95

0.99

k

m

8.5

02108_8

19.341743

37.645943

19.50

0.97

1.12

k

nm

8.8

00598_4

19.360041

37.997711

16.73

0.90

1.05

k

nm

16.0

02138_8

19.341864

37.749653

19.68

1.12

1.18

k

m

4.6

00569_4

19.360079

37.848969

19.88

1.23

1.28

k

nm

9.7

02444_8

19.342766

37.810604

18.34

0.93

1.00

k

78

4.4

00538_4

19.360250

37.932350

17.58

0.96

0.99

k

nm

13.0

06098_3

19.343510

38.050224

18.50

nd2

17.0

00422_4

19.360813

37.962696

18.18

1.00

1.12

k

nm

14.6

05998_3

19.343616

37.956688

19.21

1.39

1.52

k

nm

11.5

00381_4

19.360947

37.864788

19.81

1.62

2.35

k

nm

10.7

05951_3

19.343662

37.927708

18.06

nd1

9.9

00313_4

19.361338

37.894558

18.56

0.72

0.79

k

nm

12.0

05938_3

19.343676

37.927959

18.19

nd1

9.9

02898_10

19.361434

37.604020

22.56

nd2

13.9

00510_9

19.343704

37.796719

18.67

0.94

0.98

k

83

3.4

02924_10

19.361641

37.711676

18.04

1.47

1.82

k

nm

10.3

05870_3

19.343727

37.882679

21.96

nd1

7.3

00092_11

19.363431

37.702573

18.52

1.63

1.95

k

nm

11.7

00835_9

19.344023

37.766895

20.02

1.21

1.25

k

m?

2.9

00097_5

19.363811

37.998650

19.70

0.97

0.99

k

nm

17.6

05677_3

19.344053

37.908951

18.83

1.50

1.81

k

nm

8.7

00473_11

19.364836

37.670896

19.83

0.75

0.91

k

nm

13.4

05524_3

19.344362

38.041668

20.16

nd2

16.4

00297_5

19.365023

37.926561

22.15

nd2

15.2

01610_9

19.344818

37.740486

19.09

1.01

1.05

k

m

3.0

00553_11

19.365157

37.749285

16.26

0.92

1.02

k

nm

12.2

05014_3

19.345045

37.876141

16.24

1.06

1.17

k

m?

6.6

00448_5

19.365911

37.852960

17.32

nd2

13.6

V94

19.345139

37.743549

17.54

0.88

0.92

k

90

2.7

00819_11

19.366089

37.737134

18.77

nd2

13.0

V95

19.345295

37.792412

19.16

1.03

1.10

k

93

2.3

00521_5

19.366291

37.911656

17.26

nd2

15.4

04768_3

19.345497

37.987465

19.83

1.16

1.22

k

m?

13.1

00601_5

19.366800

37.992387

17.91

nd2

18.8

04666_3

19.345663

38.023544

15.83

nd2

15.2

01021_11

19.366890

37.806929

17.40

nd2

13.6

02716_9

19.345829

37.651981

17.69

1.45

1.73

k

nm

7.4

00793_5

19.367687

37.917070

18.32

nd2

16.5

V56(=V96)

19.345908

37.763525

17.01

0.95

0.97

k

98

1.6

01304_11

19.367749

37.637939

18.65

nd2

16.2

04392_3

19.345982

37.870571

17.90

0.88

0.92

k

m

6.1

00922_5

19.368542

37.950158

18.62

nd2

18.1

04368_3

19.346024

37.882671

19.62

1.13

1.12

k

m?

6.8

01525_11

19.368695

37.773095

18.81

nd2

14.7

04293_3

19.346100

37.838703

19.46

nd1

4.3

01695_11

19.369359

37.789309

17.96

nd2

15.2

04298_3

19.346115

37.886810

18.35

0.78

0.92

k

nm

7.0

01785_11

19.369770

37.820589

17.13

nd2

15.7

04160_3

19.346313

37.864944

17.34

1.06

1.11

k

m?

5.7

02010_11

19.370466

37.700018

19.73

nd2

16.5

03987_3

19.346600

37.910511

19.17

1.04

1.10

k

m?

8.4

01245_5

19.370613

37.897333

18.30

nd2

17.7

V75

19.346651

37.766308

17.38

0.94

0.98

s

m

1.0

02401_11

19.371975

37.721131

16.62

nd2

17.3

03687_9

19.346727

37.787651

20.13

1.07

1.45

k

m?

1.3

02419_11

19.371994

37.662943

17.30

nd2

18.2

03859_3

19.346788

37.889477

20.95

1.11

1.85

k

nm

7.1

02550_11

19.372438

37.653960

21.54

nd2

18.7

04133_9

19.347109

37.777020

18.47

0.94

0.98

k

98

0.7

00941_12

19.376714

37.722466

17.77

nd2

20.6

V76(=V85)

19.347192

37.764169

18.19

1.03

1.15

k

97

0.8

01041_12

19.376987

37.656970

17.89

nd2

21.7

V86

19.347258

37.808815

19.44

1.06

1.14

k

83

2.3

01038_12

19.377120

37.779197

20.33

nd2

20.7

V87

19.347996

37.749668

18.12

0.91

0.93

k

98

1.3

01150_12

19.377457

37.669195

17.18

nd2

21.8

05487_9

19.348234

37.677147

18.53

0.93

1.01

k

m?

5.7

01275_12

19.378092

37.727700

20.16

nd2

21.5

05673_9

19.348469

37.793930

20.61

1.29

1.62

k

m?

1.4

01807_12

19.380555

37.832929

18.99

nd2

23.4

05740_9

19.348534

37.808022

17.96

0.93

k

95

2.2

01915_12

19.381010

37.826766

20.20

nd2

23.7

06509_9

19.349110

37.684639

20.79

1.37

1.79

k

m?

5.3

02001_12

19.381172

37.629091

20.49

nd2

25.1

06532_9

19.349180

37.785137

18.01

0.91

0.95

s

m?

1.1

01961_12

19.381188

37.780646

17.87

nd2

23.6

06725_9

19.349329

37.724495

17.77

0.91

k

91

3.0

01968_12

19.381265

37.804920

18.71

nd2

23.7

06796_9

19.349415

37.769268

18.46

0.92

1.04

k

92

1.0

02176_12

19.381966

37.690587

19.60

nd2

24.6

Table 14: Long period variable stars (ordered by increasing right ascension).